Filter strainer



y 1949. N. 1.. COOPEfilDERETAL 2,475,561

I FILTER STRAINER FiIBdrFeb. 25, 1944 .2 Sheets-Sheet l y 1949- N. 1.. COOPERIDER ET AL 2,475,561

FILTER STRAINER Filed Feb. 25, 1944 r 2 Sheets-Sheet 2 INVENTOR S. Noe/ L. Cooper/den ATTORNEY.

Y Wa/fer 0. flaw/we Patented July 5, 1949 FILTER STRAINER Noel L. Cooperider and Walter 0.. Damme, Kansas City, Mo., assignors to Butler Manufacturing Company, Kansas City, Mo., a corporation of.

Missouri Application February 25, 1944, Serial No. 523,868

4 Claims. (01. 210- 184) Our inventionrelatesbroadly to newand useful improvements in strainer and filter units and .moreparticularly to afilter unit of the type used in. dry cleaning. equipment.

In. conventional "filter units for filtering dry cleaning solvents, a pluralityof filter leaves at- .tached to a-manifold are mounted in a pressuretig-ht: housing. Eachfilter leaf comprises a hollow frame covered with wire mesh or fabric.

In operation. the filter leaves are first coated withtafilter aid such-asdiatomaceous earth by .circulating the. filter aid ina suitable liquid through the unit. then. charged. to the: housing under pressure. In thelhousing. the solventpasses through the filter vaidinto the leavesandthence. to the manifold The solvent to be filtered is which. conducts i it from the housing. Contaminants in. the. solvent accumulate in. the filter aid making it periodically necessary to clean. the

muck, sludge and contaminated filter aid from the. leaves. This is. usually done by mechanical qscrapersnand. by baekwashing. i. e. reversing the flow of. liquid. through. the apparatus.

. Furthermore, it. is. frequently necessary to remove the. filter leaves f-romthe housing for thorpugh cleaning. If wire meshds used to cover the leaves, metal dust or particles in. the solvent lodge in the openings. and gradually obstruct the .flow ofliq'uid. Thisv dustis extremely difficult to remove and is not dislodged by mechanicalseraping or backwashing. If clothbags are used they become saturated with dirt and grease and must f be frequently removed and cleaned. In addition the cloth bags sometimes burst during. the backwashing operation. Removing the leaves .for cleaningis a difficult, unpleasant and time con- "suming. task; and, of course, the filter unit is necessarily idle for a considerable length of time mesh openings must be. large enough to permit free passage or the. solventbut small. enough to hold backlthe 'filteriaid. Consequently, the covers are woven to support a particular type of? filter,

aid. I'f the filter unit is .used to filter liquids I which require different types of filter aids it is necessary to keepseveral. sets of covers for the .filter leaves. This is expensive and wasteful.

an important object of our invention is to provide 'a novelfilter leaf construction that eliminatesthe conventional fabric or wire mesh cover.

Another object of our invention is to provide a filter that is easily cleaned without being. re-

moved. from" the housing.

. ,2 Still another object of our invention is to provide a filter that can be cleaned much more rapidly than the. conventional filter leaves.

Yet another object of our invention is to provide a filter thatis readily adjustable to accommodate: various types or grades of filter aid.

A: further object of. our invention is to provide adevice of the above-mentioned character wherein the filter openings are. adjustable over a wide. range so that the filter can be used without filter aid. as .a strainer to hold back only relatively large particles inta liquid.

Asti-ll further object of our invention is to provide a device of the above-mentioned character that isinexpensive to manufacture and sturdy and eiiicient in operation.

Other objectsand advantages of our invention will be apparent during the course of the following description.

"In thetdrawingsforming a part of this specificationandwherein like numerals are employed to designatelike parts throughout the same,

Fig.- 1 is a side elevation of a filter unit embodying our .i-nvention parts of the unit being broken away for a clearness of illustration, Fig. 2 isa verticalsectional view taken on the line 22,-

Fig- 3 is a fragmentary transverse sectional view taken: on the line 33-of-Fig. 1,

Fig. 4 is afragmentary transverse sectional view talrenonthe lined-=4 of. Fig. 1, and

Fig. 5 is a transverse sectional view taken on the line 5--5 of Fig. 2.

In the drawing, wherein for the purpose of illustration is shown a preferred embodiment of our invention.- the numeral 1'0 designates a cylindrica-l housing having a closed bottom. Illa andaiem'ovable top cover .lll'b. Cover 10b is carried bya pivoted arm H and is normally held in fluid tight engagementwith the housing by pressure nuts [2. A transverse partition or header l3 dividesthe housing into 'a lower compartthrough pipe lie condoned by the airrelief valve I 01. Hydrostatic pressure in the lower compartmerit lfl'c "forces the solvent through a plurality of filters l5 suspendedfrom partition I3 and into the upper compartment Illd from which it discharges through pipe [6.

The principalnovelty of this invention resides in the filterelements [5. Attention is now directed to Fig. 2 which best shows the filter construction.

Each filter element comprises a vertical helical spring I! which surrounds an elongated core IS. The upper end of the spring is fixedly attached to a nipple l5 threaded in the partition I3, and the lower end of the spring is closed by a suitable plug 20 which, in turn, is threaded on a stem lBa extending from the lower end of core 8. The core I8 is formed at its upper end with a shoulder 18b which is normally seated against nipple It by the action of spring H. The length of the spring and accordingly the spatial relation of the spring loops is controlled by the position of plug 20 on stem l8a. The plug is held in a selected adjusted position on the stem by lock nut 2|. A slip ring 22 between the spring and plug prevents the spring from twisting when the plug is rotated. The spring may have any desired cross-sectional shape. Any shape is satisfactory that will permit the spring to entirely close, i. e. permit the spring loops to press together when plug 2!! is advanced a maximum distance on the stem. When the plug is thus: positioned no liquid can pass between the spring loops. In order that the spring function as a filter it is necessary to spread the spring loops slightly by retracting plug 20. Since the spring is supported only at its ends the spring loops are uniformly spaced. The size of the openings or interstices between the spring'loops, of course, depends upon the distance the plug 20 is retracted. By carefully adjusting the plug the spring loops can be spaced apart a selected distance. When the filter is used to remove contaminants from dry cleaning solvent the spring loops should be spaced apart approximately .003 of an inch. This spacing of the loops retains the filter aid normally used for dry cleaning solvents but permits free passage of the filtered solvent between the loops. As shown in Fig. 3, core I8 is formed with a plurality of radial vanes IBc which provide longitudinal passages through which the filtered solventwithin the springs passes into the upper compartment llld. Formed on the upper end of the core is a stem I 8d which extends through nipple l9 and above the partition i3. Stem |8d is smaller in diameter than the core l8 and comprises upward extensions of vanes I 80. Any or all of the filters l5 can be removed for inspection or replacement by lifting cover ltb and unthreading nipple IS.

The filter aid around the filters gradually becomes contaminated with dirt, grease and insoluble particles such as metal dust in the solvent. These contaminants gradually fill the pores of the filter aid and obstruct flow of fluid therethrough. When this occurs, the filter aid must be removed from the filters and the filters and housing thoroughly cleaned. Removal of the filter aid is accomplished by draining the solvent from the housing through a valve controlled pipe 23 and jarring the filters to dislodge the filter aid.

The filters are simultaneously jarred to dislodge the filter aid by manually operated mechanism in the upper compartment llld. A horizontal plate 24 is supported above the projecting filter stems Hid by a plurality of springs 25. The plate can be manually lowered against the stems by rotation of eccentric cams 26 against studs 24a. The cams are keyed on a shaft 21 which extends transversely through the housing. One end of the shaft extends from the housing through a stufilng box 28 and carries a handle 29. When handle 29 is rotated to move cams 26 in the direction of the arrow in Fig. 2 the plate 24 is lowered against the action of springs to simultaneously depress the filter stems I8d. This action extends the filter screws and breaks away the cakes of filter aid which fall to the bottom of the housing and are easily removed. When cams 26 return to their original position the filters are suddenly released. Springs 25 raise plate 24 and permit the filter springs to rapidly contract. This rapid contraction together with the resultant vibration or quivering of the filter springs dislodges any remaining filter aid adhering thereto. If desired solvent can also be backwashed through the filter to thoroughly wash and clean them. If the backwashing is done with the filter springs extended all matter on or between the spring loops is efficiently removed. Liquid and muck in the housing below drain pipe 23 is removed through the cleanout valve 30.

It may thus be seen that we have accomplished the objects of our invention. We have provided a filter that is sturdily constructed and that can be easily cleaned. Cleaning is rapidly accomplished without removing the filters from the housing. It is unnecessary to enclose the main filter structure with fabric or wire mesh covers, since the springs can be accurately adjusted to regulate the spatial relation of the spring loops and adjustment is effective over a sufliciently wide range so that the device can be used with different filter aids and either as a filter or strainer.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred embodiment of the same and that various changes in the size shape and arrangement of parts may be resorted to without departing from the spirit of our invention or the scope of the appended claims.

Having thus described our invention, we claim:

1. In a filter apparatus a housing, a horizontal perforated partition dividing the housing into upper and lower compartments, an inlet to the housing below the partition and an outlet above the partition a helical spring suspended from the partition, a plug closing the lower end of the spring, a core within the spring, means limiting upward movement of the core unit in the spring, a stem on the lower end of the core extending through the plug, means for moving the plug along the stem and securing it in a selected adjusted position, a stem on the upper end of the core extending through and above the partition, and means movable against the projecting end of the upper stem to depress the same and extend said spring to release matter lodged between the spring loops.

2. In a filter apparatus a housing, a horizontal perforated partition dividing the housing into upper and lower compartments, an inlet to the housing below the partition and an outlet above the partition a helical spring having a closed lower end suspended from the partition, a core within the spring, and adjustable means coacting with the core to constrict or expand the spring whereby to control the spatial relation of the spring loops at a first interval, a stem on the upper end of the core extending through and above the partition, and means movable against the projecting stem to depress the same and extend the spring to release matter lodged between the spring loops.

3. In a filter apparatus, a housing, a perforated horizontal partition dividing the housing into upper and lower compartments, an inlet in the housing below the partition and an outlet above the partition, a plurality of helical springs suspended from the partition, each spring having a closed lower end, a core within each spring extending the length thereof and terminating at its upper end in a stem which extends through and above the partition, a common plate engaging the upper ends of all of said stems, and mechanism for depressing said plate thereby to extend said springs and release matter lodged between the spring loops.

4. A filter apparatus as in claim 3 wherein said mechanism comprises a rotatable cam adapted to bear against and reciprocate said plate as the 15 Number cam turns.

NOEL L. COOPERIDER. WALTER O. DAMME REFERENCES CITED UNITED STATES PATENTS Number Name Date 408,487 Jewell Aug. 6, 1889 1,279,611 Timmins Sept. 24, 1918 2,068,282 Strindberg Jan. 19, 1937 2,197,971 Elze et al Apr. 23, 1940 2,301,430 Malanowski Nov. 10, 1942 FOREIGN PATENTS Country Date 502,103 Great Britain Mar. 10, 1939 527,259 Great Britain Oct. 4, 1940 636,693 France Jan. 14, 1928 

